This invention relates generally to a process for conversion of carbonium ion precursors and nitrites to amines.
U.S. Pat. No. 2,457,660 discloses a process for preparation of N-tertiary alkyl amides from carbonium ion precursors and nitrites in the presence of an acidic catalyst. The list of suitable acidic catalysts includes ammonium bisulfate. This reference does not disclose a process for conversion of the amides to the corresponding amines.
The problem addressed by this invention is to reduce the need for a strong acid catalyst in a process for conversion of carbonium ion precursors and nitriles to amines.
In one embodiment, the present invention is a method for preparation of an amine from a carbonium ion precursor and a nitrile. The method comprises the steps of: (a) contacting the carbonium ion precursor and the nitrile with aqueous ammonium hydrogen sulfate to produce an amide; and (b) hydrolyzing the amide to the amine.
In another embodiment, the present invention is directed to a substantially waste-free method for preparation of an amide from a carbonium ion precursor and a nitrile. The method comprises the steps of (a) contacting the carbonium ion precursor and the nitrile with aqueous ammonium hydrogen sulfate to produce an amide; (b) recovering diammonium sulfate from an aqueous phase; and (c) decomposing diammonium sulfate by heating to produce ammonia and ammonium hydrogen sulfate.